Q - Have a 04 f250 6.0 its smoking bad out tail pipe and smell like desil fuel what could be my problem

A - If you are getting diesel fuel out of the tail pipe there is an issue with an injector. Either it is fueling at the wrong time, the tip is cracked, or the orings on the body of the injector are letting it leak past. I would remove all the injectors and inspect them if a scan tool doesn't tell you which one is misfiring.